Lesson: Rotational Kinetic Energy Physics • 9th Grade

In this lesson, we will learn how to calculate the rotational kinetic energy of a rotating object from its moment of inertia and its angular velocity.

Lesson Plan

Students will be able to

use to calculate the rotational kinetic energy of an object,
understand that is the rotational analogue of .

Lesson Video

Lesson Worksheet

Q1:

Which of the following relations describes how the rotational kinetic energy, , of a rotating object varies with the moment of inertia, , of that object around its axis of rotation?

Q2:

A baseball bat that is being swung to hit a baseball has rotational kinetic energy of 1,490 J and an angular velocity of 12.1 rad/s. What is the moment of inertia of the object around its axis of rotation? Give your answer to one decimal place.

Q3:

A rotating object has rotational kinetic energy of 4,000 J. A torque is applied to the object and 2,600 J of rotational work is done accelerating the object. If the object has a moment of inertia of , what is its angular velocity after the torque has been applied? Give your answer to one decimal place.